The invention relates to equipment for roasting commodities such as coffee, hazelnuts, peanuts and similar commodities.
Equipment of the type used for roasting coffee, nuts and other beans consists essentially in a feed system, a device in which the raw commodity is subjected to treatment, a hot air generator, an extractor, a separator-and-disposal unit, a cooling system and a discharge system.
The raw commodity will be supplied by the feeder to the treatment device in prescribed, and variable quantities.
The treatment device consists in one, or at most two revolving drums that rotate about respective horizontal axes and are connected with the hot air generator and the extractor: the extractor is designed to sustain a vacuum in the drums such as will ensure a continual intake of hot air from the generator. Hot air leaves the drum and is exhausted by the extractor into the separator-and-disposal unit, generally a cyclone separator, which proceeds to remove any husks, skins or similar waste from the air stream.
The roasted commodity is then conveyed from the drums to the cooling system, where it is stirred in a container exposed to the surrounding environment, before being transferred finally to the discharge system.
In equipment of the type thus outlined, the full charge-roast-discharge cycle of the rotating drum, or drums, has to be implemented fragmentarily, as it is impossible to fill and empty the drum at one and the same time.
Thus it happens that operation of the equipment, when considered in its entirety, is non-continuous, with down time accumulating in proportion to the capacity of the roasting drums.
Accordingly, the object of the invention is to design roasting equipment capable of continuous operation.